mineral

Celestite (Celestine)

Strontium sulfate (SrSO4)

Hardness: 3 to 3.5 on Mohs scale; Color: Pale blue, colorless, or white; Luster: Vitreous (glassy) to pearly; Crystal Structure: Orthorhombic; Cleavage: Perfect in one direction; Specific Gravity: 3.95 to 3.97.

Hardness: 3 to 3
Color: Pale blue, colorless, or white
Luster: Vitreous (glassy) to pearly

Identified March 21, 2026More mineral →

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Physical properties

Formation & geological history

Formed primarily in sedimentary rocks, often within geodes or as replacement deposits in limestone and dolomite. It crystallizes from strontium-rich hydrothermal fluids or evaporating saline lake waters. Most commercial specimens are from the Jurassic or Cretaceous periods.

Uses & applications

Major source of the element strontium, used in pyrotechnics (fireworks) for red flames, glass manufacturing, and electronics. Highly valued as a collector's mineral and frequently used in 'metaphysical' crystal healing circles.

Geological facts

The largest celestite geode in the world is 'Crystal Cave' in Ohio, USA, which is 35 feet deep and wide enough for people to walk through. Despite its blue appearance, the name 'Celestite' is derived from the Latin word 'caelestis,' meaning heavenly.

Field identification & locations

Identify by its distinctive pale blue color, high weight for its size (high density), and brittle, tabular or prismatic crystals. Common locations include Madagascar (Sakoany mine), USA (Ohio/Michigan), and Italy (Sicily). Collectors should handle with care as it is soft and light-sensitive.